The U.S. Supreme Court and researchers at Duke University are looking at the same question. When does redistricting move from using a partisan advantage into gerrymandering? Lisa Soronen, executive director of the State and Local Legal Center, said the Alabama Legislative Black Caucus vs. Alabama case currently being decided by the Supreme Court concerns a redistricting plan set up by the courts in 1990…. Soronen said the justices have several big picture questions to decide, such as how much use of race is too much. Everyone agrees that race has to be considered in redistricting, but it can’t be the predominant factor. Just what that means is for the court to decide, she said. …. Jonathan Mattingly, professor of mathematics and statistical sciences at Duke University, has developed a mathematical model that may prove useful for trying to decide that fine line between political advantage and gerrymandering….